(1) Field of the Invention
The present invention relates to transflective liquid crystal display devices, and more particularly to a transflective liquid crystal display device that enables transmissive display at a wide viewing angle, and also enables an excellent visibility even under a very light environment such as outdoors.
(2) Description of the Related Art
A transflective liquid crystal display device having a transmissive portion and a reflective portion within one sub-pixel has been employed as a display for a mobile device.
On the other hand, a liquid crystal display device of the IPS system has been known as a liquid crystal display device. In the liquid crystal display device of the IPS system, pixel electrodes and a common electrode are formed on the same substrate, an electric field is applied between the pixel electrodes and the common electrode, and liquid crystal is rotated within a substrate plane to conduct light and dark control. For that reason, the liquid crystal display of the IPS system has a feature that the shading of a display image is not reversed when a screen is viewed from an angle.
To utilize the above feature, for example, Japanese Patent Application Laid-Open Publication No. 2006-171376 proposes that the transflective liquid crystal display device is constituted by using the liquid crystal display device of the IPS system.